No matter how much you already know about a subject, there is always room to improve your knowledge. If you are hoping to become an expert in any area — including sustainability — a big tip from successful people around the world is to keep on reading!

Self-made billionaire Tai Lopez believes that the key to success is through reading daily. His method can be applied to any industry, including sustainability, and many of the world’s millionaires and billionaires cite a voracious appetite for reading as their competitive advantage in their industry. So if you want to gain a competitive edge in helping businesses go green? Pick up a book — or three.

“Everybody wants a six-pack body,” Lopez said. “But where are the people who want six-pack brains?”

You can use his 4-step plan to better consume information, improve your knowledge, and step up your business game.

1. Select books with value — gossip magazines and romance novels aren’t going to help you gain useful knowledge of the world or your industry. Your best bet when it comes to making a selection? Lopez suggests books written by authors with proven track records for success. So who are your sustainability effort heroes? Perhaps select one of Joel Makower’s books, which highlight the intersection of business, sustainability and innovation or sustainable living writer Lucy Siegle. Really, whoever inspires you is a good place to start.

2. Next you need to split your time between reading three types of books — a classic (more than 50 years old), a how-to or other book related to the sustainability industry so you are sharpening your skill set daily, and an autobiography or biography that you can read before bed to inspire and motivate you.

3. When you have your material selected you need to actually set aside the time to read. Every. Single. Day. Lopez splits his day into thirds, spending 1/3 of it consuming raw data to be used later; another 1/3 seeing how what he has read can be applied personally through work, life and wealth; and the final 1/3 actually implementing and analyzing what has been learned.

4. Invest time and money into reading. If you aren’t investing the time and money to read more and better content, you are not going to see improvement. The bottom line: the more you learn, the more you can earn. If you can work these tips into your life, you will undoubtedly see a growth in your awareness and marketability when it comes to providing sustainability guidance for your clients.